I'm a 38 y/o gay male in a monogamous relationship. I've been on an extended research trip in Europe for the past three months. Twelve days ago, I had a reckless encounter with a guy I didn't know before. We gave each other unprotected oral sex without ejaculation inside the mouth, but I probably was exposed to pre-seminal fluid. Oral sex was somewhat rough, so afterwards my throat was a bit sore and red, and I also think that at one point, after the guy had left, I noticed a tiny bit of blood in my spit after having cleared my throat.
Right after the encounter, I started panicking, partly because of guilt for cheating on my partner, partly because of fear that I may have exposed myself to HIV (I'm indeed a bit paranoid about it and in retrospect the guy seems quite promiscuous, although we didn't meet at a bar or a sex club). I couldn't sleep all night and only somewhat calmed down the next day after having browsed dozens of web pages and reading about the relatively low risk from oral sex without ejaculation.
However, exactly eight days after the possible exposure, I developed diarrhea, stomach cramps and fever with some backpain and headache. Of course, I had another panic attack, being sure it was ARS. The fever persisted for about two days (37.5-38.5 deg. C), diarrhea for another day or two--it seems to be going away right now, although not yet completely. I didn't notice any swollen lymph nodes, sore throat, or rash. Admiteddly, a friend I have here had similar symptoms last week--diarrhea, stomach cramps, headache, but no fever--so it is indeed possible that there is some stomach infection circulating.
How much do you think I should worry? I do know that HIV infection can't be diagnosed through any symptoms and that only tests are conclusive, but I'm having these bouts of worry and I'm scared of having to wait for three months to test. Does it make any sense for me to take a PCR test and when exactly? How much are my symptoms actually consistent with ARS? Is it possible that I indeed contracted some stomach infection, but that fever from ARS only coincided with it, since my friend who had the same infection never developed fever? I know that my questions may sound silly, but I need a level headed opinion and I don't have anyone here to ask. Thanks.